It is known in the art to provide a two-stroke cycle air compressor having or more cylinders driven by an internal combustion engine also having one or more cylinders. The compressor and engine cylinders may be formed within a common frame, or crankcase, and have pistons connected to a common crankshaft and the engine cylinders may be operated on either a two or four-stroke cycle.
As shown in U.S. Pat. No. 4,480,968, the subject matter of which is incorporated herein by reference as a further teaching of the present invention, the engine and compressor are preferably housed in a common crankcase and utilize a common blower both to charge and scavenge the engine cylinders and to charge the compressor cylinders, thereby increasing their volumetric charging efficiency.
Engine compressor units may be made for example by modifying engines from a line of known two-cycle diesel engines having uniflow scavenging. The modified engines are provided with nonported cylinder liners and special cylinder heads in some of the cylinders preferably those of one bank of V-type engines, to operate on a two-stroke compressor cycle. Connection of the compressor cylinder head inlet ports with the engine air box allows using pressurized charging air from the engine blower for charging the compressor cylinders also. A turbocharger driven by exhaust from the engine cylinders may be mounted to provide compressed intake air to the charging blower.